Melatonin Does Not Link the Eyes to the Rest of the Circadian System in Quail: A Neural Pathway Is Involved
- 1 December 1990
- journal article
- research article
- Published by SAGE Publications in Journal of Biological Rhythms
- Vol. 5 (4), 349-361
- https://doi.org/10.1177/074873049000500406
Abstract
Blinding by enucleation has a dramatic effect on the circadian activity rhythm of Japanese quail. The activity patterns of enucleated birds held under 24-hr light—dark cycles are disrupted, although entrainment can persist in many birds. In constant darkness (DD), blinded birds are rendered arrhythmic. These results demonstrate that the eyes are a major component of the circadian system, and that insofar as enucleation produces arrhythmicity in DD, the eyes' role is not merely a photosensory one. The eyes of quail can synthesize and secrete the hormone melatonin, which has been implicated as a blood-borne messenger relaying timing information between elements of the circadian system in some avian species. However, the way in which the eyes communicate with the rest of the circadian system in quail appears to be neural, since (1) optic nerve section produces the same effects as blinding by enucleation on the circadian activity rhythm, and (2) eyes subjected to optic nerve section retain their ability to synthesize and secrete melatonin.Keywords
This publication has 18 references indexed in Scilit:
- The Quail's Eye: A Biological ClockJournal of Biological Rhythms, 1990
- Retinohypothalamic Projections and the Suprachiasmatic Nucleus in BirdsBrain, Behavior and Evolution, 1989
- Does a Biological Clock Reside in the Eye of Quail?Journal of Biological Rhythms, 1988
- Retinohypothalamic projection and suprachiasmatic nucleus of the house sparrow, Passer domesticusJournal of Comparative Neurology, 1987
- Melatonin Rhythms in Quail: Regulation by Photoperiod and Circadian PacemakersJournal of Pineal Research, 1985
- Methoxyindoles and Photoreceptor Metabolism: Activation of Rod SheddingScience, 1983
- Vertebrate circadian rhythms: Retinal and extraretinal photoreceptionCellular and Molecular Life Sciences, 1982
- The role of the pineal organ and the suprachiasmatic nucleus in the control of circadian locomotor rhythms in the Java sparrow,Padda oryzivoraJournal of Comparative Physiology A, 1981
- Synchronization of a circadian rhythm in pinealectomized European starlings by daily injections of melatoninJournal of Comparative Physiology A, 1978
- Melatonin: Effects on the Circadian Locomotor Rhythm of SparrowsScience, 1976